Truck troubles... Help? Ideas?


Buckslayer

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Last week my truck wouldn't even turn over one morning, and being that the battery was 5 years old, I thought maybe that was it. Well I decided to keep the booster pac in my truck in case it happened again (I didn't think I left anything on, but wasn't sure)... Well, yesterday morning it happened again, so after checking my alternator, which was charging good, I went out and bought a battery and put it in.

This morning I went out AND IT WAS DEAD! So I knew it was something draining my battery. I was sure I turned everything off. I plugged my battery charger in, and started to charge my truck battery outside the garage. I called Advanced Auto parts, and told them the story, knowing they still had my core. They couldn't refund my money and give me my core back because I had already installed the battery (only for 24 hours mind you...) So I'm sitting in my truck and I hear a whining sound. I get closer and notice my air is running without the key in the ignition. Then I tried the vent switch. It works! No key, but the switch works between vent pathways...

So in the meantime I got into the fuse box and unplugged the relay to the blower, so that nothing is drawing power. My truck started up, and now is charging itself.

Question is, I need heat, and don't know what happened? The heat and vents work, but they just don't shut of when in the "OFF" position. They continue to drain power the whole time the key isn't in. Does anyone have any ideas where to start?

Thanks, Matt

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Re: Truck troubles... Help? Ideas?

Hey guys... its not the relay. I switched it out with another one of the same kind and it did it again. I got to thinking, Does that switch operate the vents on vacuum suction? Cause if it did this is a dead end and I have a short elsewhere in the vehicle. I think there is a vacuum canister that would continue to operate the vent louvres after the truck has been shut off. When I moved the switch for a while, and all the vacuum got used up, the switch no longer operated the louvres. Thats why I'm thinking along that line.

For now I guess to be safe I'm just going to have to disconnect my battery anytime the truck is sitting for more than an hour or so... I have no clue how to find a short in one of hundreds of circuits in the vehicle so I'm probably going to give it to my cousin who is manager of a Ford Quicklane garage and have them figure it out.

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Re: Truck troubles... Help? Ideas?

Shaun, it was the airflow control knob that was working after the key was removed from the ignition, not the blower switch. Sorry if I made it seem like it was the blower switch itself.

Another bit of info is that after about 25mins of driving, I lose control of the airflow. When I use the airflow control knob it doesn't switch between vent paths, and no air seems to come out. The blower will still adjust between levels 1,2,3, and 4 and will sound louder as it blows more air... even though nothing is coming out the vents.

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Re: Truck troubles... Help? Ideas?

I agree William. I've created my next plan of attack. It involves waiting 45 minutes for all vehicle modules to power down, then taking my voltmeter and inserting the probes inline with the negative battery cable (not across terminals). Then, I will remove each fuse one by one to see if I can find which electrical system has the short. The slowing/stopping of current flow on my meter would indicate this when I remove the fuse to the shorted circuit right?

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Re: Truck troubles... Help? Ideas?

[ QUOTE ]

I agree William. I've created my next plan of attack. It involves waiting 45 minutes for all vehicle modules to power down, then taking my voltmeter and inserting the probes inline with the negative battery cable (not across terminals). Then, I will remove each fuse one by one to see if I can find which electrical system has the short. The slowing/stopping of current flow on my meter would indicate this when I remove the fuse to the shorted circuit right?

[/ QUOTE ]

Yep, you are correct. That'd be the parasidic draw test, put the meter in amps and connect it in series between the negative cable and negative post on the battery. Let it sit for a while until everything goes to sleep. You should have between 10 and 25mA draw.

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Re: Truck troubles... Help? Ideas?

Something popped to my mind when I read Leo's post. Does your dome lamp work when you open the door? I know we have problems with the door jam switches with our Sunfires and Cavaliers, the radio won't turn off until the door is opened, but if the door jam switch sticks it'll stay on constantly and the dome lamp will not work. Causing the battery to drain.

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Re: Truck troubles... Help? Ideas?

[ QUOTE ]

Something popped to my mind when I read Leo's post. Does your dome lamp work when you open the door? I know we have problems with the door jam switches with our Sunfires and Cavaliers, the radio won't turn off until the door is opened, but if the door jam switch sticks it'll stay on constantly and the dome lamp will not work. Causing the battery to drain.

[/ QUOTE ]

Its not that Leo, Shaun... I checked. I did the parasitic drain test tonight and couldn't find anything. I have an appointment on monday with my Ford dealer. Since my cousin is the service manager he will take it in and find the cause for free. Fixing it will still cost money but that I can do on my own once they find it. grin.gif I'll report back monday or tuesday when I know what it is. Thanks for all the help!

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